Illumination for optical scan and measurement

ABSTRACT

Optical scanning with an optical probe composed of an elongated cylinder of transparent material mounted upon an optical scanner body; one or more sources of scan illumination mounted in the probe distally or proximally with respect to the scanner body and projecting scan illumination longitudinally through the probe; a radially-reflecting optical element mounted in the probe having a conical mirror on a surface of the radially-reflecting optical element, the mirror oriented so as to project scan illumination radially away from a longitudinal axis of the probe with at least some of the scan illumination projected onto a scanned object; a lens mounted in the probe between the radially-reflecting optical element and the scanner body and disposed so as to conduct to an optical sensor scan illumination reflected from the scanned object.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the benefit and priority of U.S.Provisional Patent Application No. 61/871,002, filed Aug. 28, 2013, andentitled “Optical Systems For Measuring A Drilled Hole In A StructureAnd Methods Relating Thereto.”

BACKGROUND

Much research and manufacturing today requires precision metrology, veryaccurate measurement and inspection of mass produced and customcomponents, components in wind turbines, jet engines, combustion gasturbines, nuclear reactors, ships, automobiles, other aviationcomponents, medical devices and prosthetics, 3D printers, plastics,fiber optics, other optics for telescopes, microscopes, cameras, and soon. The list is long, and the problems are large. In inspecting anairframe, for example, an inspection checks the diameter and circularityof each of thousands of holes at different depths to ensure that eachhole is perpendicular to a surface, circular in cross section as opposedto elliptical, not conical, not hourglass-shaped, and so on. Suchinspections are performed by human quality assurance inspectors, whoinspect large groups of holes at one time, extremely laboriously. When adrill bit or mill head becomes chipped or otherwise damaged, its currenthole and all its potentially hundreds or thousands of subsequent holesare out of tolerance, none of which are identified until inspection.

Prior art attempts at high precision measurement include focalmicroscopy for fringe pattern analysis, that is image analysis bycomparison with a pre-image of a correct part, all difficult to deployand not very accurate. Other prior art includes capacitive probes suchas described for example in U.S. 2012/0288336. Such capacitive probes,however, take measurements in only one direction at a time, requiringmultiple measurements to assess a part, never assembling a completeimage of the inside of a part. Moreover, a capacitive probe must fittightly into or onto a part to be measured, aligned closely to thecenter axis of the hole, and for calibration purposes, must have thesame probe-to-hole-side separation at all times—because its capacitanceis calibrated according to the thickness of the layer of air between theprobe and a component to be scanned or measured. When such a capacitiveprobe identifies a problem with a part, and the part is redrilled orremilled to a larger size, the capacitive probe must be swapped out to alarger diameter probe in order to remeasure the part.

Prior art optical scanners typically are too bulky to move with respectto a part under inspection. Such optical scanners are typically mountedon a fixture with a scanned part in a jig that moves with respect to thescanner. This fixed physical orientation between the optical scanner anda part to be scanned or measured means that there are always aspects ofthe part that cannot be reached, measured, scanned, or imaged by such aprior art optical scanner. This limitation of prior art has given riseto so-called multi-sensor metrology devices that include both opticalscan capability and also tactile sensors that attempt to measureportions of a part that optical scan illumination cannot reach—all in anattempt to build a scanner that can scan a part accurately andcompletely. One manufacturer of metrology equipment, for example,combines three types of sensor probes, a light section sensor, ashape-from-focus (SFF) sensor, and a tactile sensor, all of which aresaid to work in unison to achieve optimum measurement, even in areaswhere scan illumination cannot reach. There continues in the industrysome real need for an optical scanner with better reach.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-9 set forth line drawings and block diagrams of exampleapparatus for optical scanning

FIGS. 10A, 10B, 10C, 11A, and 11B illustrate several examples of lineforming apparatus.

FIGS. 12A and 12B illustrate further example apparatus for opticalscanning.

FIGS. 13A-13E set forth five line drawings of example apparatus foroptical scanning.

FIG. 14 sets forth a flow chart illustrating an example method ofoptical scanning.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Example apparatus for optical scanning according to embodiments of thepresent invention are described with reference to the accompanyingdrawings, beginning with FIG. 1. FIG. 1 sets forth a line drawing andblock diagram of example apparatus for optical scanning that includes anoptical probe (106) mounted upon an optical scanner body (103). Thelocations of components of example scanning apparatus are sometimesdescribed in this specification in terms of orientation with respect toa scanner body. Components are described as ‘distal’ when farther fromthe scanner body and ‘proximal’ when nearer.

The optical probe is capable of movement for optical scanning withrespect to both the interior and the exterior of a scanned object (201).In embodiments, the same optical probe can scan aspects of objects ofdiffering size, different hole diameters, different cavity depths,different exterior dimensions, all with the same probe.

The terms ‘scan,’ ‘scanned,’ ‘scanning,’ and the like, as used here,refer to illuminating a scanned object with scan illumination that isvery bright with respect to ambient light levels—so that one or morepartial images of the scanned object, portions of the scanned objectbrightly illuminated by scan illumination, are captured through probeoptics and an optical sensor. Apparatus for optical scanning accordingto embodiments of the present invention typically also utilize thesepartial images to measure certain characteristics of a scanned object orto construct from the partial images a larger or more complete image ofa scanned object, including, for example, a 3D image of part or all of ascanned object, interior or exterior.

Optical scanners according to many embodiments of the present inventionhave the capability of acquiring by imaging and profilometry a “fullservice profile” of a scanned object. Such a full service profileoptionally includes both a high precision 3D scan and also a highprecision surface profile of an object. The high accuracy 3D scanachieves microresolution regarding volumetric aspects of an object, thatis, linear measurement along volumetric aspects, length, width,circumference, diameter, cavity or hole depths, and so on, withprecision on the order of micrometers. The surface profile is effectedas optical profilometry, measurements of roughness or smoothness ofsurfaces, through known methods of focus detection, intensity detection,differential detection, Fourier profilometry, or the like, alsotypically with precision on the order of micrometers.

A scanned object (201) is represented in the example of FIG. 1 as athree-sided box with interior and exterior surfaces. In this example,the probe (106) is illustrated as scanning interior surfaces of thescanned object (201), although the probe is capable of scanning theexterior surfaces as well. The optical probe (110), shown here incross-section, is housed in a probe wall (119) composed of an elongatedcylinder of transparent material mounted on the optical scanner body(103). The probe wall (119) is composed of optical glass, quartzcrystal, fused silica, or the like. The optical scanner body isconfigured for mounting on a robotic transport, to be hand held, or tobe mounted on a jig or fixture, so that the probe is capable of movementwith respect to the scanned object (201).

The optical probe (110) in this example includes one or more sources(182) of scan illumination mounted in the probe distally from thescanner body and projecting scan illumination (123) longitudinallythrough the probe toward the scanner body. In this example, the sources(182) of scan illumination (123) are mounted in an end cap (135) that isinstalled or fabricated to fit inside the cylinder formed by the probewall (106) at the end of the probe distal from the scanner body. Thesources (182) of scan illumination may be implemented as light emittingdiodes (‘LEDs’), collimated LEDs, lasers, or with other sources of scanillumination as may occur to those of skill in the art.

The optical probe (110) in the example of FIG. 1 also includes aradially-reflecting optical element (226) mounted in the probe betweenthe sources (182) of scan illumination and the scanner body (103). Theradially-reflecting optical element has a conical mirror (231) on asurface of the radially-reflecting optical element distal from thescanner body and proximal to the sources (182) of scan illumination. Theconical mirror (231) is oriented so as to project scan illumination(134) radially away from a longitudinal axis (190) of the probe with atleast some of the scan illumination projected onto a scanned object(201).

The optical probe (106) in the example of FIG. 1 also includes a lens(114) mounted in the probe between the radially-reflecting opticalelement (226) and the scanner body (103) and disposed so as to conductto an optical sensor (112) scan illumination (136) reflected from thescanned object (201). The lens (114) is composed of several lenselements (115) and spacers (125) that fit the lens as a whole snugglyinto a lens housing formed in this example by the probe wall itself(119). The lens elements (115) are composed of optical glass, quartzcrystal, fused silica, or the like, and the lens elements are configuredin a lens assembly (114) within the probe so as to focus reflected scanillumination (136) on the optical sensor (112).

The optical sensor (112) is mounted in the scanner body (103) anddisposed with respect to the lens (114) so as to receive through thelens the scan illumination (136) reflected from the scanned object. Theoptical sensor may be implemented as a charged coupled device (‘CCD’),as a complementary metal oxide semiconductor (‘CMOS’) sensor, as acharge injection device (‘CID’), and in other ways as will occur tothose of skill in the art. The optical sensor is disposed within theoptical scanner body so as to capture, from the scan illumination (136)reflected from the scanned object, an image of at least a portion of thescanned object. The portion of the scanned object so imaged is theportion illuminated by scan illumination (134). The scan illuminationtypically is sufficiently bright that elements illuminated only byambient illumination can appear dark in captured images. In embodiments,a sequence of partial images, portions illuminated by scan illuminationand captured as the probe is moved with respect to a scanned object, areused for multiple measurements or aggregated to build a larger image.Measurements of a scanned object can include, for example, diameter,circularity, and perpendicularity of drilled or milled holes and othercavities, countersink dimensions, fastener flushness with respect to asurface of a scanned object, measurements indicating manufacturingdefects in scanned objects, cracks, burrs, or the like, and measurementsindicating defects in machine tools, drill bits, mill heads, and thelike. Images of a scanned object can be constructed by a controller as atwo-dimensional image aggregated from a sequence of partial images, or,for example, into a three-dimensional image by building point clouds,forming a rough image by connecting points into triangles, and smoothingby known algorithms the rough image into a finished image.

In this example, the sensor (112) is operatively coupled to a controller(156) through data bus (155), and the controller is coupled to computermemory (168) through memory bus (157). The controller is configured todetermine, from the scan illumination reflected from the scanned objectand captured as images by the sensor, measurements of the scanned objectand, in some embodiments at least, also to work with the sensor tocapture images and store them in computer memory. The controller (156)may be implemented as a Harvard architecture microcontroller with acontrol program in memory (168), a generally programmable Von Neumannarchitecture microprocessor with a control program in memory (168), afield programmable gate array (‘FPGA’), a complex programmable logicdevice (‘CPLD’), an application-specific integrated circuit (‘ASIC’), ahard-wired network of asynchronous or synchronous logic, and otherwiseas will occur to those of skill in the art.

The apparatus of FIG. 1 also includes optical masking material (232,234, 236, 238) disposed on the exterior of the probe (106) so as to maskscan illumination noise (206, 207, 222). The masking material in thisexample also includes masking (244) disposed within the interior of theprobe wall. Scan illumination rays (206, 207) represent scanillumination that reflects twice from the scanned object, with ray (206)flowing all the way through the transparent probe housing (119) andpresenting a second reflection (207) from the scanned object (201).Reflection (207) presents an undesired secondary reflection which wouldform a false image if it were allowed to promulgate through the lens(114) to the sensor (112). Such a false image represents scanillumination noise (222). Remember that scan illumination typically isvery bright, much brighter than ambient illumination, so that even smallamounts of scan illumination noise can hamper measurement and imagingbased on reflected scan illumination. As an aid to explanation, rays(206, 207) are illustrated here as they would flow without masking, withray (206) traveling through the probe housing and ray (207) striking thetop element of the lens. Readers will recognize, however, that themasking material at locations (234, 236) would effectively block boththe traverse of ray (206) through the probe and the entry of ray (207)to the lens, thus reducing or eliminating entirely the scan illuminationnoise (222). Also note that there is a lot of bright scan illuminationtraveling through the distal portion of the probe (182, 123, 231). Themasking material (244) within the probe wall itself (106) prevents strayscan illumination from being reflected or propagated directly down fromthe distal portion of the probe through the probe wall (119) toward thelens (114) and the sensor (112).

Readers will recognize also that the bottom (208) of theradially-reflecting optical element (226) is effectively a flat piece ofpotentially reflective optical material, glass, quartz, or the like,proximal to the scanner body (103) and proximal to the lens (114). Thusthe bottom (208) of the radially-reflecting optical element (226) itselfcan provide unwanted reflections and can also permit unwantedreflections from the back side of the conical mirror (231). The bottomsurface (208) of the radially-reflecting optical element (226) thereforehas disposed upon it additional optical masking material so as tofurther mask scan illumination noise.

The illustrated locations for optical masking in the example of FIG. 1are for explanation, not for limitation. Masks (232, 234) are the samepiece of masking material wrapped around the outside of the cylindricalprobe wall shown here in cross section, and masks (236, 238) are thesame piece. The example of FIG. 1 therefore illustrates three locations(232-234, 236-238, 183) for optical masking for the probe. Otherlocations for optical masking on an optical probe may occur to those ofskill in the art, and all such locations are well within the scope ofthe present invention.

The apparatus of FIG. 1 also includes a heat sink (240) mounted on anouter surface of the probe (106) opposite the sources (182) of scanillumination and a heat sink (242) mounted on the outer surface of theprobe (106) adjacent to the scanner body (103). The sources (182) ofscan illumination in this example are powered by a battery (185) mountedin the end cap (135) of the probe (106), and the combination ofelectronics and light sources in the end cap can become heated inoperation in embodiments. Similarly, the optical sensor (112), thecontroller (156), the computer memory (168), and other electronics inembodiments can be mounted in the optical scanner body near the base ofthe probe which also can become heated in operation. The illustratedlocations for heat sinks in the example of FIG. 1 are for explanation,not for limitation. The example of FIG. 1 illustrates two locations forheat sinks, one location (240) at the tip of the probe distal from thescanner body and another location (242) at the base of the probeproximal to the scanner body. Other locations for heat sinks forscanning apparatus may occur to those of skill in the art, and all suchlocations are well within the scope of the present invention.

For further explanation, FIG. 2 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 2 is similar to the example apparatus of FIG.1, including as it does sources (182) of scan illumination, aradially-reflecting optical element (226), a lens (114), an opticalsensor (112), a controller (156), computer memory (168), various masks(232-238, 244), and heat sinks (240,242), all mounted and disposedwithin and upon a cylindrical wall (119) of an optical probe (106) andan optical scanner body (103) as described above with reference to FIG.1.

The scanning apparatus in the example of FIG. 2, however, also includesor more supplemental sources (187) of scan illumination (191) mounted inthe probe (106) distally from the scanner body (103). The supplementalsources (187) are mounted in the end cap (135) inside the cylindricalwall (119) of the probe (106) and powered by the same battery (185). Thesupplemental sources (187) can be implemented with LEDs, collimatedLEDs, lasers, or other sources as may occur to those of skill in theart. The supplemental sources (187) are oriented in the end cap so thatthey project supplemental scan illumination (191) radially away from alongitudinal axis (190) of the probe. The supplemental sources (187) areoriented so that they project supplemental scan illumination (191)directly from the sources (187) through the transparent probe wall (119)onto a scanned object (201) with no intervening mirror or other optics.The supplemental sources (187) are oriented so that the supplementalscan illumination (191) strikes the scanned object (201) at an angle(209) that is different from the angle (210) at which the scanillumination (134) from the conical mirror (231) strikes the scannedobject.

The lens (114) is disposed within the probe so as to conduct to theoptical sensor (112) the supplemental scan illumination (191) asreflected (211) from the scanned object (201) as well as the scanillumination (136) from sources (182) as reflected (134, 136) from theconical mirror (231) and the scanned object (201). The optical sensor(112) also is disposed with respect to the lens (114) so as to receivethrough the lens the supplemental scan illumination (211) reflected fromthe scanned object (201) as well as the scan illumination (136) fromsources (182) as reflected (134, 136) from the conical mirror (231) andthe scanned object (201).

The supplemental scan illumination (191) is a supplemental aid tooptical measurement of a scanned object. In embodiments, the total scanillumination over a smooth surface, even including supplementalillumination, is generally uniform as a probe scans an object by movingwith respect to the object.

Although the supplemental scan illumination (191) and the scanillumination (134) from the conical mirror (231) strike a scanned object(201) at different angles (209, 210), on balance, the total scanillumination over a smooth surface is quite uniform. The total scanillumination over a rough surface, however, is not uniform, insteadbeing characterized by bright spots and shadows where both sources ofillumination strike a rough portion of a surface. In the example of FIG.2, both instances of scan illumination (134, 191) strike a burr (192) ina surface of a scanned object. The burr (193) is an example of a rough,sharp edge remaining on a part after machining or stamping. The presenceof such a burr is a manufacturing defect to be detected and repaired,because such a burr presents a risk of interference with precise fittingof parts. The image of the burr as captured through the lens and theoptical sensor in the example of FIG. 2 will present a bright aspect(193) that is much brighter than the evenly illuminated smooth surfacesurrounding the burr. The image will also present a shadow (194) that ismuch darker than the evenly illuminated smooth surface surrounding theburr. All of which eases the controller's image analysis in measuring ascanned object for the presence of manufacturing defects.

For further explanation, FIG. 3 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 3 is similar to the example apparatus of FIG.1, including as it does sources (182) of scan illumination, aradially-reflecting optical element (226), a lens (114), an opticalsensor (112), a controller (156), computer memory (168), various masks(232-238, 244), and heat sinks (240,242), all mounted and disposedwithin and upon a cylindrical wall (119) of an optical probe (106) andan optical scanner body (103) as described above with reference to FIG.1.

The example apparatus of FIG. 3, however, also includes aradially-gathering optical element (227) mounted in the probe betweenthe radially-reflecting optical element (226) and the lens (114). Theradially-gathering optical element has a conical mirror (233) on asurface of the radially-gathering optical element proximal to the lens(114). The conical mirror (233) is oriented so as to gather toward thelens scan illumination (136) reflected from the scanned object. Theradially-reflecting optical element (226) and the radially-gatheringoptical element (227) are mounted back-to-back with a layer of maskingmaterial (183) between them.

The radially-gathering optical element (227) is so-named by way ofcontrast with the radially-reflecting optical element (226). Theradially-reflecting optical element (226) reflects scanning illumination(123) radially onto a surface of a scanned object, whereas theradially-gathering optical element (227) gathers by reflecting throughthe lens the radial scanning illumination (136) reflected from thescanned object. The radially-gathering optical element (227) is disposedwithin the cylindrical wall of the probe so that the conical mirror iscapable of gathering illumination (136) from a scanned object that isreflected at a larger angle (181) than is possible with some other probeconfiguration. This enables additional masking (232, 234, 236, 238),reduces the risk of scan illumination noise (222), improves the qualityof reflected scan illumination (136), improves quality of measurement,and improves imaging quality.

As noted above, although the supplemental scan illumination (191) andthe scan illumination (134) from the conical mirror (231) strike ascanned object (201) at different angles, on balance, the total scanillumination over a smooth surface is quite uniform. The total scanillumination over a rough surface, however, is not uniform, insteadbeing characterized by bright spots and shadows where both sources ofillumination strike a rough portion of a surface. In the example of FIG.3, both instances of scan illumination (134, 191) strike a crack (196)in a surface of a scanned object. The crack (196) is a manufacturingdefect to be detected and repaired. The image of the crack as capturedthrough the lens and the optical sensor in the example of FIG. 3 willpresent a bright aspect (193) that is much brighter than the evenlyilluminated smooth surface surrounding the crack. The image will alsopresent a shadow (194) that is much darker than the evenly illuminatedsmooth surface surrounding the crack. All of which again eases thecontroller's image analysis in measuring a scanned object for thepresence of manufacturing defects.

For further explanation, FIG. 4 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 4 is similar to the example apparatus of FIG.1-3, including as it does a source (182) of scan illumination, a lens(114), an optical sensor (112), a controller (156), computer memory(168), various masks (236, 238) and heat sinks (240, 242), all mountedand disposed within and upon a cylindrical wall (119) of an opticalprobe (106) and an optical scanner body (103) as described above withreference to FIGS. 1-3. In the example of FIG. 4, however, a source(182) of scan illumination is mounted on the probe (106) proximally tothe scanner body (103) and disposed so as to project scan illumination(123) distally through the probe away from the scanner body. The source(182) of scan illumination in this example is mounted on the exterior ofthe cylindrical wall (119) of the probe (106) by mounting fixture (197)and disposed upon the exterior of the probe so as to project scanillumination (123) at an angle (220) with respect to a longitudinal axis(190) of the probe. That is, the source shines scan illumination fromoutside the cylindrical probe wall (119) distally up through the probetowards a radially-reflecting optical element (227).

The example probe of FIG. 4 includes the radially-reflecting opticalelement (227), which is mounted in the probe distally from the scannerbody, in fact, in this example, inside the probe's cylindrical wall(119) near the tip of the probe. The radially-reflecting optical element(229) has a conical mirror (231) disposed upon a surface (208) of theradially-reflecting optical element proximal to the scanner body. Thesurface (208) upon which the mirror is formed is fashionedasymmetrically with respect to a longitudinal axis (190) of the probe,so that the conical mirror on the radially-reflecting optical element(229) is an asymmetric conical mirror (231). The asymmetry of thesurfaces of the asymmetrical conical mirror accommodates the fact thatthe source (182) of scan illumination in this example projects scanillumination (123) onto the conical mirror at an angle (220) withrespect to a longitudinal axis (190) of the probe (190). The asymmetryof the conical mirror (231) effectively orients the mirror so as toaccomplish the projection of scan illumination (134) radially away froma longitudinal axis (190) of the probe—so that at least some of the scanillumination is projected onto a scanned object (201).

For further explanation, FIG. 5 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 5 is similar to the example apparatus of FIG.4, including as it does a source (182) of scan illumination mountedproximally to the scanner body, a radially-reflecting optical element(229) with a conical mirror (231) mounted in the probe distally from thescanner body, a lens (114), an optical sensor (112), a controller (156),and computer memory (168), all mounted and disposed within and upon acylindrical wall (119) of an optical probe (106) and an optical scannerbody (103) similarly as described above with reference to FIG. 4. Thesource (182) of scan illumination (123) in the example of FIG. 5 ismounted in the probe proximally to the scanner body and distally withrespect to the radially-reflecting optical element (229). In the exampleof FIG. 5, however, the source (182) is disposed or oriented so as toproject scan illumination (123) distally with respect to the lens, infront of the lens, and transversely through the probe to a mirror (230).The mirror (230) is disposed with respect to the source (182) of scanillumination so as to reflect the scan illumination (123) longitudinallythrough the probe away from the lens, away from the scanner body, andtoward the radially-reflecting optical element (229). In a fashionsimilar to the example of FIG. 4, the conical mirror (231), with noapparent asymmetry in this example, is oriented so as to project thescan illumination (134) radially away from a longitudinal axis (190) ofthe probe—so that at least some of the scan illumination is projectedonto a scanned object (201).

For further explanation, FIG. 6 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 6 is similar to the example apparatus of FIG.4, including as it does a source (182) of scan illumination mountedproximally to the scanner body, a radially-reflecting optical element(229) with a conical mirror (231) mounted in the probe distally from thescanner body, a lens (114), an optical sensor (112), a controller (156),and computer memory (168), all mounted and disposed within and upon acylindrical wall (119) of an optical probe (106) and an optical scannerbody (103) similarly as described above with reference to FIG. 4. Thecontroller (156) and memory (168) are shown here disposed within thescanner body, but that is for explanation only, not for limitation.Readers will recognize that the controller and memory can be locatedoutside the scanner body and connected to the optical sensor (112)through a data bus such as a Universal Serial Bus (‘USB’) or the like.

The source (182) of scan illumination (123) in the example of FIG. 6 ismounted in the probe proximally to the scanner body with respect to thelens (114), that is, behind the lens. The source (182) is disposed so asto project scan illumination past the lens through an optical conductor.In this example, the optical conductor for the scan illumination is thetransparent wall (119) of the probe itself. The probe in this exampleincludes a first mirror (228) disposed with respect to the opticalconductor (119) so as to reflect the scan illumination (123) distallywith respect to the lens, in front of the lens, and transversely throughthe probe to a second mirror (230). The second mirror (230) is disposedwith respect to the first mirror so as to reflect the scan illumination(123) longitudinally through the probe away from the lens (114), awayfrom the scanner body (103), and toward the radially-reflecting opticalelement (229) and the conical mirror (231). In a fashion similar to theexample of FIG. 5, the conical mirror (231), again with no apparentasymmetry, is oriented so as to project the scan illumination (134)radially away from a longitudinal axis (190) of the probe—so that atleast some of the scan illumination is projected onto a scanned object(201).

For further explanation, FIG. 7 sets forth a line drawing and blockdiagram of example apparatus for optical scanning that includes anoptical probe (106), illustrated here in cross-section. The opticalprobe is capable of movement for optical scanning with respect to boththe interior and the exterior of a scanned object (201, 202, 203). Oneor more scanned objects are represented in the example of FIG. 7 withthree drawing elements (201, 202, 203). These three elements areoriented among the apparatus in FIG. 7 so that they could be extendedand joined so that the three surfaces upon which scan illumination isproject could be three surfaces of an interior of a scanned object. Thethree surfaces in other embodiments can represent external surfaces ofthree separate scanned objects.

The optical probe includes light conducting apparatus (119) disposed soas to conduct scan illumination (123) from a source (182) of scanillumination through the probe. The light conducting apparatus in thisexample is a tubular wall of the probe itself, composed of opticalglass, quartz crystal, or the like, that conducts scan illumination froma source (182) of such illumination to line forming apparatus (224) orreflecting apparatus (226) in the probe. The scan illumination may beconducted from a source (182) to the probe wall (119) for transmissionto a line former or reflector by, as in the example here, optical fiber(121), or through optical glass, a conical reflector, a reflaxicon, andin other ways as will occur to those of skill in the art. The sources(182) themselves may be implemented with LEDs (186), lasers (184), orwith other sources of scan illumination as may occur to those of skillin the art.

The optical probe (106) in the example of FIG. 7 includes lightreflecting apparatus (226), a ‘reflector,’ disposed so as to projectscan illumination (123) radially (134) away from a longitudinal axis(190) of the probe with at least some of the scan illumination projectedonto a scanned object (201, 202). In this example, some of the scanillumination is radially projected (134) and some of the scanillumination is projected in a fan (111) that forms a line (110) upon ascanned object. The reflector (226) can be implemented, for example, asa half-silvered mirror when the scan illumination (123) is all of a sameor similar wavelength, so that the portion of the scan illumination thatstrikes the silvered portion of the mirror is reflected radially. Insome embodiments of apparatus for optical scanning according toembodiments of the present invention, however, the scan illumination isof two wavelengths, and the reflector is composed of a layer of dichroicmaterial that reflects one wavelength radially and passes through theother wavelength to line forming apparatus (224) that projects a fan oflight into a line on a scanned object.

The example apparatus of FIG. 7 is said to project “at least some” ofthe radial scan illumination onto a scanned object. In manyapplications, because of the shape of the particular scanned object,only part of the radial illumination will strike a scanned object and bereflected (136) back into the probe for use in measurements or imaging.And that result is perfectly fine. So long as sufficient reflection(136) is present to support measurement or imaging, there is no need torequire all of the radial illumination (134) to strike and reflect fromthe scanned object back into the probe.

The optical probe (106) in the example of FIG. 7 also includes opticalline forming apparatus (224) disposed so as to project scan illuminationas a line of scan illumination (110) with at least some of the scanillumination projected onto the scanned object. In some embodiments,scan illumination for optical line forming is collimated, or if notexactly collimated, at least collimated to the extent that most rays ofscan illumination are traveling in generally the same direction whenthey encounter line forming apparatus. In the example of FIG. 7, theprobe wall itself (119) and the frustration rings (204) work together bytotal internal frustration of light rays traveling at angles steepenough to refract through the outer edge of either the probe wall itselfor the frustration rings. The frustration rings can be implemented, forexample, with an optical epoxy resin whose index of refraction matchesthe index of refraction of the probe wall. In this way, rays of scanillumination traveling at angles of incidence low enough to reflect backinto the probe wall are guided into the refraction rings and refractedout, leaving in the probe wall only those rays of scan illuminationtraveling in the same direction through the probe wall toward the lineforming apparatus. As discussed in more detail below, the line formingapparatus itself can be implemented in a variety of ways, including, forexample, Powell lenses, collimators integrated with Powell lenses,refractive lenses, with diffractive optics, and so on.

The optical probe (106) in the example of FIG. 7 also includes a lens(114) disposed so as to conduct, through the probe to an optical sensor(112), scan illumination (136, 137) reflected from a scanned object. Thelens (114) is composed of several lens elements (115) and spacers (125)that fit the lens as a whole snuggly into a lens housing formed in thisexample by the probe wall itself (119). The lens elements (115) includeelements L0 through L10, which are configured to effect two focal planes(104, 108). Lens elements L1-L10 effect a focal plane (104) that isdisposed with respect to the probe so that the radial projection of scanillumination (134) is in focus where it strikes a scanned object (201,202). Lens element L0 is an optical field-of-view expander thatimplements a wide-angle effect for a front view through the lens (114)as a whole. The wide-angle effect of L0 also disposes a second focalplane (108) distally from the front of the probe (106) so that aprojected line (110) of scan illumination is in focus where a fan (111)of scan illumination strikes a scanned object (203). Lens elementsL0-L10 conduct through the probe to an optical sensor (112) scanillumination (137) reflected from a line (110) of scan illuminationprojected upon a scanned object (203). Lens elements L1-L10 conductthrough the probe to an optical sensor (112) scan illumination (136)reflected from a radial projection (134) of scan illumination upon ascanned object (201, 202). The optical sensor may be implemented as acharged coupled device (‘CCD’), as a complementary metal oxidesemiconductor (‘CMOS’) sensor, as a charge injection device (‘CID’), andin other ways as will occur to those of skill in the art.

The example apparatus of FIG. 7 also includes an optical scanner body(103) with the probe (106) mounted upon the optical scanner body. Theoptical scanner body has mounted within it the source or sources (182)of scan illumination conductively coupled to the light conductingapparatus. In this example of course, the light conducting apparatus isimplemented as the probe body (119), and the conductive coupling betweenthe sources of illumination (182) and the light conducting apparatus(119) is effected with optical fiber (121).

In the example apparatus of FIG. 7, the optical sensor (112) is disposedwith respect to the lens (114) so as to receive through the lens scanillumination (136, 137) reflected from a scanned object, and the opticalsensor is disposed within the optical scanner body so as to capture,from the scan illumination reflected through the lens from the scannedobject, an image of at least a portion of the scanned object. Again itis said ‘at least a portion.’ Many embodiments of scanning apparatusaccording to embodiments of the present invention evidence littleconcern that there is a complete image of a scanned object from anyparticular capture, because an image of any desired completeness isconstructed in such embodiments from a sequence of partial images.

The example apparatus of FIG. 7 also includes a controller (156),coupled to the sensor (112) through data bus (155), with the controllerconfigured to determine from scan illumination (136, 137) receivedthrough the lens (114) by the sensor (112) measurements of the scannedobject (201, 202, 203). The controller (156) may be implemented as aHarvard architecture microcontroller with a control program in memory(168), a generally programmable Von Neumann architecture microprocessorwith a control program in memory (168), field programmable gate array(‘FPGA’), complex programmable logic device (‘CPLD’),application-specific integrated circuit (‘ASIC’), a hard-wired networkof asynchronous or synchronous logic, and otherwise as will occur tothose of skill in the art.

The controller (156) is coupled through a memory bus (157) to computermemory (168), which in this example is used to store the controller'smeasurements (314) or captured images (315) of a scanned object.Measurements (314) of a scanned object can include for example:

-   -   diameter, circularity, and perpendicularity of drilled or milled        holes and other cavities,    -   countersink dimensions, depth and diameter,    -   fastener flushness with respect to a surface of a scanned        object,    -   dimensions of milled cavities having irregular internal        structures,    -   measurements indicating manufacturing defects in scanned        objects, cracks, burrs, or the like, and    -   measurements indicating defects in tools, drill bits, mill        heads, and the like,    -   and so on.

Regarding manufacturing defects, the controller in example embodimentsis programmed to determine according to image processing algorithms thelocation of a light source and probe in an image, and the light sourceand probe are configured for an expected surface finish for material ofwhich a scanned object is composed. If there is a significant deviationin surface finish indicating a crack or if there are burrs, reflectedscan illumination does not appear as radially symmetric on the sensor.Rather it will have significant local variations in its appearance. Thatthese variations are greater than a threshold is an indicator of amanufacturing defect such as a burr or crack. Burrs can also beidentified from white light images of the entrance and exit of a drilledor milled cavity because the edge of the cavity will not appear smooth.

For further explanation, FIG. 8 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 8 is very similar to the example apparatus ofFIG. 7, except for the exclusion of optical line forming apparatus fromthe example of FIG. 8. Embodiments that provide radial projection ofscan illumination with no provision for optical line forming providesubstantial optical scanning and measurement capabilities that are, insome embodiments at least, less expensive to implement than apparatusthat includes both line forming and radial projection.

The example apparatus of FIG. 8 includes an optical probe (106), againillustrated in cross-section. The optical probe is capable of movementfor optical scanning with respect to both the interior and the exteriorof a scanned object (201, 202). One or more scanned objects arerepresented here with two elements (201, 202). These two elements areillustrated in cross-section so that, extended in three dimensions andjoined, they could represent an interior surface of a scanned object.Alternatively, the two surfaces could represent external surfaces of twoseparate scanned objects, all of which is explained in more detailbelow.

The optical probe includes light conducting apparatus (119) disposed soas to conduct scan illumination (123) from a source (182) of scanillumination through the probe. The light conducting apparatus in thisexample is a tubular wall of the probe itself, composed of opticalglass, quartz crystal, or the like, that conducts scan illumination froma source (182) of such illumination to line reflecting apparatus (226)in the probe. The scan illumination may be conducted from a source (182)to the probe wall (119) for transmission to a line former or reflectorby optical fiber, through optical glass, a conical reflector, areflaxicon, and in other ways as will occur to those of skill in theart. The sources (182) themselves may be implemented with LEDs (186),lasers (184), or with other sources of scan illumination as may occur tothose of skill in the art.

The optical probe (106) in the example of FIG. 8 includes lightreflecting apparatus (226), a ‘reflector,’ disposed so as to projectscan illumination (123) radially (134) away from a longitudinal axis(190) of the probe with at least some of the scan illumination projectedonto a scanned object (201, 202). The reflector (226) can beimplemented, for example, as a sectioned, silvered, optical conicalmirror disposed within the probe so that scan illumination that strikesthe mirror is reflected radially (134). The example apparatus of FIG. 8is said to project “at least some” of the radial scan illumination ontoa scanned object. In many applications, because of the shape of theparticular scanned object, only part of the radial illumination willstrike a scanned object and be reflected (136) back into the probe foruse in measurements or imaging, a result that is perfectly fine. So longas sufficient reflection (136) is present to support measurement orimaging, there is no need to require all of the radial illumination(134) to strike and reflect from the scanned object back into the probe.

The optical probe (106) in the example of FIG. 8 also includes a lens(114) disposed so as to conduct, through the probe to an optical sensor(112), scan illumination (136) reflected from a scanned object. The lens(114) is composed of several lens elements (115) and spacers (125) thatfit the lens as a whole snuggly into a lens housing formed in thisexample by the probe wall itself (119). The lens elements (115) includeelements L1 through L10, which are configured to effect a focal plane(104) that is disposed with respect to the probe so that the radialprojection of scan illumination (134) is in focus where it strikes ascanned object (201, 202). Lens elements L1-L10 conduct through theprobe to an optical sensor (112) scan illumination (136) reflected froma radial projection (134) of scan illumination upon a scanned object(201, 202).

In the example apparatus of FIG. 8, the optical sensor (112) is disposedwith respect to the lens (114) so as to receive through the lens scanillumination (136) reflected from a scanned object, and the opticalsensor is disposed so as to capture, from the scan illuminationreflected through the lens from the scanned object, an image of at leasta portion of the scanned object. The example apparatus of FIG. 8 alsoincludes a controller (156), coupled to the sensor (112) through databus (155), with the controller configured to determine from scanillumination (136) received through the lens (114) by the sensor (112)measurements of the scanned object (201, 202). The controller (156) iscoupled through a memory bus (157) to computer memory (168), which isused to store the controller's measurement or captured images of ascanned object.

For further explanation, FIG. 9 sets forth a line drawing and blockdiagram of additional example apparatus for optical scanning. Theexample apparatus of FIG. 9 is very similar to the example apparatus ofFIG. 7, except for the exclusion of radial reflection apparatus from theexample of FIG. 9. Embodiments that provide distal line projection ofscan illumination with no provision for radial projection providesubstantial optical scanning and measurement capabilities that are, insome embodiments at least, less expensive to implement than apparatusthat includes both line forming and radial projection.

The example apparatus of FIG. 9 includes an optical probe (106), againillustrated in cross-section. The optical probe is capable of movementfor optical scanning with respect to both the interior and exterior of ascanned object (203). A scanned object is represented here with onedrawing element (203). This element is oriented in FIG. 9 so that itcould represent any surface, oriented either on the exterior of ascanned object or as an interior surface, any surface that can bereached by projected scan illumination (111).

The optical probe includes light conducting apparatus (119) disposed soas to conduct scan illumination (123) from a source (182) of scanillumination through the probe. The light conducting apparatus in thisexample is a tubular wall of the probe itself, composed of opticalglass, quartz crystal, or the like, that conducts scan illumination froma source (182) of such illumination to line forming apparatus (224) inthe probe. The scan illumination may be conducted from a source (182) tothe probe wall (119) for transmission to a line former by optical fiber,optical glass, a conical reflector, a reflaxicon, and in other ways aswill occur to those of skill in the art. The sources (182) themselvesmay be implemented with LEDs (186), lasers (184), or with other sourcesof scan illumination as may occur to those of skill in the art.

The optical probe (106) in the example of FIG. 9 also includes opticalline forming apparatus (224) disposed so as to project scan illuminationas a line of scan illumination (110) with at least some of the scanillumination projected onto the scanned object. In some embodiments,scan illumination for optical line forming is collimated, or if notexactly collimated, at least collimated to the extent that most rays ofscan illumination are traveling in generally the same direction whenthey encounter line forming apparatus. In the example of FIG. 9, theprobe wall itself (119) and the frustration rings (204) work together bytotal internal frustration of light rays traveling at angles steepenough to refract through the outer edge of either the probe wall itselfor the frustration rings. The frustration rings can be implemented, forexample, with an optical epoxy resin whose index of refraction matchesthe index of refraction of the probe wall. In this way, rays of scanillumination traveling at angles of incidence low enough to reflect backinto the probe wall are guided into the refraction rings and refractedout, leaving in the probe wall only those rays of scan illuminationtraveling in the same direction through the probe wall toward the lineforming apparatus. As discussed in more detail below, the line formingapparatus itself can be implemented in a variety of ways, including, forexample, Powell lenses, collimators integrated with Powell lenses,refractive lenses, with diffractive optics, and so on.

The optical probe (106) in the example of FIG. 9 also includes a lens(114) disposed so as to conduct, through the probe to an optical sensor(112), scan illumination (137) reflected from a scanned object. The lens(114) is composed of several lens elements (115) and spacers (125) thatfit the lens as a whole snuggly into a lens housing formed in thisexample by the probe wall itself (119). The lens elements (115) includeelements L0 through L10. Lens element L0 is an optical field-of-viewexpander that implements a wide-angle effect for a front view throughthe lens (114) as a whole. The wide-angle effect of L0 also disposes afocal plane (108) distally from the front of the probe (106) so that aprojected line (110) of scan illumination is in focus where a fan (111)of scan illumination strikes a scanned object (203). Lens elementsL0-L10 conduct through the probe to an optical sensor (112) scanillumination (137) reflected from a line (110) of scan illuminationprojected upon a scanned object (203).

In the example apparatus of FIG. 9, the optical sensor (112) is disposedwith respect to the lens (114) so as to receive through the lens scanillumination (137) reflected from a scanned object, and the opticalsensor is disposed with respect to the lens so as to capture, from thescan illumination reflected through the lens from the scanned object, animage of at least a portion of the scanned object. The example apparatusof FIG. 9 also includes a controller (156), coupled to the sensor (112)through data bus (155), with the controller configured to determine fromscan illumination (137) received through the lens (114) by the sensor(112) measurements of the scanned object (203). The controller (156) iscoupled through a memory bus (157) to computer memory (168), which isused to store the controller's measurements or captured images of ascanned object.

For further explanation of line forming apparatus, FIGS. 10A, 10B, and10C set forth illustrations of several examples of line formingapparatus. The example apparatus of FIG. 10A includes a Powell lens(116) that forms scan illumination (123) into a fan (111) ofillumination that forms a line (110) upon striking a scanned object. APowell lens, named for its inventor Dr. Ian Powell, is an optical lensformed with an aspheric roof that effects spherical aberrationsufficient to distribute scan illumination evenly along a line. The scanillumination (123), as used with the Powell lens in the example of FIG.10A, is assumed to be either laser light or light that is otherwisecollimated upon leaving its source (182). The line (110) for ease ofillustration is show here as geometrically straight, although readerswill recognize that in fact the actual shape of the line in practicalapplication often will not be perfectly straight, but will conform tothe shape of the surface upon which it is projected.

The apparatus in the example of FIG. 10B includes a Powell lens (116)integrated with a collimator (124) that together form scan illumination(123) into a fan (111) of illumination that forms a line (110) uponstriking a scanned object. The scan illumination (123), as used with thePowell lens and the collimator in the example of FIG. 1B, is LED lightor at least light that is not otherwise collimated when it leaves itssource (182). The collimator (124) includes a positive or refractivelens (126) and an aperture (128) situated at a focal point (117) of thelens proximal to the light source, so that rays of light traversing theaperture are refracted by the lens into collimated rays.

The apparatus in the example of FIG. 10C includes a positive orrefractive lens (126) that, when illuminated with collimated scanillumination (123), forms the scan illumination into a fan (111) ofillumination that forms a line (110) upon striking a scanned object. Thescan illumination (123) in this example is laser light or light that isotherwise collimated when or after it leaves its source (182). The lens(126) in this example projects the collimated illumination (123) througha focal point (117) distal from the light source (182) so that rays oflight traversing the lens are refracted into a fan (111) that forms aline (110) upon a scanned object.

For further explanation, FIGS. 11A and 11B set forth illustrations offurther example line forming apparatus. FIG. 11A is a detailed calloutof the optical probe of FIG. 11B. The example apparatus of FIGS. 5A and5B includes a diffractive optic lens (136) that, when illuminated bylight (123) from a source of illumination (182) projects scanillumination as a fan (111) disposed at a predetermined angle (140) withrespect to a longitudinal axis (190) of an optical probe (106) in whichthe lens (136) is installed. The angle (140) is determined according toknown optical properties of the lens (136), and the longitudinal axis(190) is any axis that is disposed generally in parallel to any centeraxis of the probe (106).

For further explanation, FIG. 12A sets forth a line drawing of exampleapparatus for optical scanning that includes an optical probe (106)capable of motion for optical scanning with respect to both the interior(304) and the exterior (302) of a scanned object (202). The exampleapparatus of FIG. 12A includes an optical scanner body (102) with theoptical probe (106) mounted upon the optical scanner body. The opticalscanner body (102) is configured to be hand held so that the probe (106)is capable of movement by hand for optical scanning with respect to thescanned object, including both movement within the interior (304) of thescanned object (202) and movement with respect to the exterior (302) ofthe scanned object.

For further explanation, FIG. 12B sets forth a line drawing of exampleapparatus for optical scanning that includes an optical probe (106)capable of motion for optical scanning with respect to both the interior(304) and the exterior (302) of a scanned object (202). The exampleapparatus of FIG. 12B includes an optical scanner body (103) with theoptical probe (106) mounted upon the optical scanner body. The opticalscanner body (103) is configured for mounting upon an end effector (101)of a robotic transport (162) so that the probe is capable of movement bythe robotic transport for optical scanning with respect to the scannedobject, including both movement within the interior (304) of the scannedobject (202) and movement with respect to the exterior (302) of thescanned object.

For further explanation, FIGS. 13A-13E set forth five line drawings ofexample apparatus for optical scanning each of which includes an opticalprobe (106) capable of motion for optical scanning with respect to boththe interior (304) and the exterior (302) of a scanned object (202).Each of the example apparatus FIGS. 7A-7E includes an optical scannerbody (103) with the optical probe (106) mounted upon the optical scannerbody. The optical scanner body (103) in each of FIGS. 7A-7E isconfigured for mounting upon an end effector of a robotic transport or ajig or fixture so that the probe is capable of movement by thetransport, jig, or fixture for optical scanning with respect to ascanned object (202), including both movement within the interior (304)of the scanned object and movement with respect to the exterior (302) ofthe scanned object. Readers will appreciate by now that the scanner bodyand probe also could be hand held and moved by hand.

In the example of FIG. 13A, the scanner body (103) and probe (106) arepositioned so that surfaces of the scanned object (202) are illuminatedwith radial illumination (134) from the probe. When the probe is movedacross the top of the scanned object, radial illumination strikes boththe exterior (302) and interior (304) of the scanned object in adirection that enables measurement characteristics of interior aspect ofthe scanned object. In this example, the interior is formed as a holethat is drilled or milled into the scanned object, and the measurementsare countersink depth (206) and total depth (218) of the hole.

In the example of FIG. 13B, the scanner body (103) and probe (106) arepositioned so that surfaces of the scanned object are illuminated with afan (111) of scan illumination that forms a line (110) when itencounters the scanned object, not a perfectly straight line, but a linethat conforms to the surface it strikes. When the probe is moved acrossthe top of the scanned object (202), the fan of illumination strikesboth the exterior (302) and the interior (304) of the scanned object ina direction that enables measurement of characteristics of a hole thatis drilled or milled into the scanned object, in this example, ameasurement of countersink diameter (208).

In the example of FIG. 13C, the scanner body (103) and probe (106) arepositioned so that surfaces of the scanned object (202) are illuminatedwith a fan (111) of scan illumination that forms a line (110) when itencounters the scanned object. When the probe is moved across the top ofthe scanned object, the fan of illumination strikes the exterior of thescanned object, including the top surface of a fastener (216) that isdisposed within the a hole drilled or milled into the scanned object.The probe moves in a direction that enables measurement ofcharacteristics of the scanned object, in this example, a measurement ofthe flushness (210) of the fastener with respect to a top surface of thescanned object.

In the example of FIG. 13D, the scanner body (103) and probe (106) arepositioned so that interior surfaces of the scanned object areilluminated with radial illumination (134) from the probe. When theprobe is moved within the interior of the scanned object (202), radialillumination strikes interior surfaces of the scanned object in adirection that enables measurement of characteristics of the interior.In this example, the measurements are diameter and circularity (212) ofa hole that is drilled or milled into the scanned object.

In the example of FIG. 13E, the scanner body (103) and probe (106) arepositioned so that interior surfaces of the scanned object areilluminated with radial illumination (134) from the probe. When theprobe is moved within the interior of the scanned object, radialillumination strikes interior surfaces of the scanned object in adirection that enables measurement of a characteristic of the interior.In this example, the measurement is perpendicularity (214) of a holethat is drilled or milled into the scanned object.

For further explanation, FIG. 14 sets forth a flow chart illustrating anexample method of optical scanning with an optical probe (106) that iscapable of motion for optical scanning with respect to both the interiorand the exterior of a scanned object. In the method of FIG. 14, theoptical probe (106) is mounted upon an optical scanner body (103) thathouses an optical sensor and one or more sources of scan illumination.This specification uses the apparatus illustrated in FIG. 7 also toexplain the method of FIG. 14, so that reference numbers in thefollowing discussion refer to drawing elements both on FIG. 14 and alsoon FIG. 7.

The method of FIG. 14 includes moving (252) the probe to optically scanboth the interior (304) and the exterior (302) of a scanned object(202). Moving the probe can be effected by moving (254) the probe by arobotic transport or by hand (256). Robotic transports includenumerically controlled machines as well as devices for computer aidedmanufacturing. A probe moved by hand can be hand held or held in a jigwhile the jig is operated by hand.

The method of FIG. 14 includes conducting (258) scan illumination (111,134), by light conducting apparatus (119) disposed within the probe(106), from a source (182) of scan illumination through the probe. Themethod of FIG. 14 also includes projecting (260) scan illumination, bylight reflecting apparatus (226) disposed within the probe, radially(134) away from a longitudinal axis (190) of the probe with at leastsome of the scan illumination projected onto the scanned object.

The method of FIG. 14 also includes projecting (262) scan illumination,by optical line forming apparatus (224) disposed within the probe, as aline (110) of scan illumination with at least some of the scanillumination projected onto the scanned object. Projecting (262) scanillumination as a line can be carried out by projecting scanillumination as a fan (111) of scan illumination that projects a line(110) when it encounters a surface of a scanned object, interior orexterior. Projecting (262) scan illumination as a line can also becarried out by projecting scan illumination as a fan (111) of scanillumination disposed at a predetermined angle (140 on FIGS. 5A and 5B)with respect to a longitudinal axis (190) of the probe. Projecting scanillumination as a line can be implemented through a Powell lens, acollimating optical element integrated with a Powell lens, a diffractiveoptic lens, a refractive optic lens, and no doubt in other ways thatwill occur to those of skill in the art, all of which are well withinthe scope of the present invention.

The method of FIG. 14 also includes conducting (264) by a lens (114)disposed within the probe (106), through the probe to an optical sensor(112), scan illumination (136, 137) reflected from the scanned object.The method of FIG. 14 also includes receiving (266), by the opticalsensor (112) through the lens (114), scan illumination (136, 137)reflected from the scanned object. The method of FIG. 14 also includesdetermining (268), by a controller (156) operatively coupled to theoptical sensor (112) from the received scan illumination (136, 137),measurements (314) of the scanned object. The method of FIG. 14 alsoincludes capturing (270), by an optical sensor (112) disposed within anoptical scanner body with the probe mounted upon the scanner body, fromscan illumination (136, 137) reflected through the lens (114) from thescanned object (201, 202, 203), one or more images (315) of at least aportion of the scanned object.

Example embodiments of the present invention are described largely inthe context of fully functional apparatus for optical scanning Readersof skill in the art will recognize, however, that the present inventionalso may be embodied in one or more methods of use, methods ofmanufacture, and in a computer program product disposed upon computerreadable storage media for use with any suitable data processing system.Such computer readable storage media may be any storage medium formachine-readable information, including magnetic media, optical media,or other suitable media. Examples of such media include magnetic disksin hard drives or diskettes, compact disks for optical drives, magnetictape, and others as will occur to those of skill in the art. Personsskilled in the art will immediately recognize that any computer systemhaving suitable programming means will be capable of executing the stepsof the method of the invention as embodied in a computer programproduct. Persons skilled in the art will recognize also that, althoughsome of the example embodiments described in this specification areoriented to software installed and executing on computer hardware,nevertheless, alternative embodiments implemented as firmware or ashardware are well within the scope of the present invention. Theflowcharts and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof computer apparatus, methods, and computer program products accordingto various embodiments of the present invention.

It will be understood from the foregoing description that modificationsand changes may be made in various embodiments of the present inventionwithout departing from its true spirit. The descriptions in thisspecification are for purposes of illustration only and are not to beconstrued in a limiting sense. The scope of the present invention islimited only by the language of the following claims.

What is claimed is:
 1. Apparatus for optical scanning, the apparatuscomprising: an optical probe comprising an elongated cylinder oftransparent material mounted upon an optical scanner body; one or moresources of scan illumination mounted in the probe distally from thescanner body and projecting scan illumination longitudinally through theprobe toward the scanner body; a radially-reflecting optical elementmounted in the probe between the sources of scan illumination and thescanner body, the radially-reflecting optical element comprising aconical mirror on a surface of the radially-reflecting optical elementdistal from the scanner body, the mirror oriented so as to project scanillumination radially away from a longitudinal axis of the probe with atleast some of the scan illumination projected onto a scanned object; alens mounted in the probe between the radially-reflecting opticalelement and the scanner body and disposed so as to conduct to an opticalsensor scan illumination reflected from the scanned object; and theoptical sensor mounted in the scanner body and disposed with respect tothe lens so as to receive through the lens the scan illuminationreflected from the scanned object.
 2. The apparatus of claim 1 furthercomprising optical masking material disposed on the exterior of theprobe so as to mask scan illumination noise.
 3. The apparatus of claim 1wherein the optical element further comprises a flat surface of opticalglass proximal to the scanner body, the surface having optical maskingmaterial disposed on the surface so as to mask scan illumination noise.4. The apparatus of claim 1 further comprising a heat sink mounted on anouter surface of the probe opposite the sources of scan illumination anda heat sink mounted on the outer surface of the probe adjacent to thescanner body.
 5. The apparatus of claim 1 further comprising the opticalsensor disposed within the optical scanner body so as to capture, fromthe scan illumination reflected from the scanned object, an image of atleast a portion of the scanned object.
 6. The apparatus of claim 1further comprising a controller operatively coupled to the opticalsensor, the controller configured to determine, from the scanillumination reflected from the scanned object, measurements of thescanned object.
 7. The apparatus of claim 1 further comprising theoptical scanner body configured for mounting upon an end effector of arobotic transport so that the probe is capable of movement by therobotic transport for optical scanning with respect to the scannedobject, including both movement within the scanned object and movementwith respect to the exterior of the scanned object.
 8. The apparatus ofclaim 1 further comprising the optical scanner body configured to behand held so that the probe is capable of movement by hand for opticalscanning with respect to the scanned object, including both movementwithin the scanned object and movement with respect to the exterior ofthe scanned object.
 9. The apparatus of claim 1 wherein: the apparatusfurther comprises one or more supplemental sources of scan illuminationmounted in the probe distally from the scanner body and projectingsupplemental scan illumination radially away from a longitudinal axis ofthe probe so that the supplemental scan illumination strikes the scannedobject at an angle that is different from the angle at which the radialillumination from the mirror strikes the scanned object; the lens isfurther disposed so as to conduct to the optical sensor supplementalscan illumination reflected from the scanned object; and the opticalsensor is further disposed with respect to the lens so as to receivethrough the lens the supplemental scan illumination reflected from thescanned object.
 10. The apparatus of claim 1 further comprising aradially-gathering optical element mounted in the probe between theradially-reflecting optical element and the lens, the radially-gatheringoptical element comprising a conical mirror on a surface of theradially-gathering optical element proximal to the lens, the conicalmirror oriented so as to gather toward the lens scan illuminationreflected from the scanned object.
 11. The apparatus of claim 1 furthercomprising a controller operatively coupled to the optical sensor, thecontroller configured to determine, from the scan illumination reflectedfrom the scanned object, measurements of the scanned object.
 12. Theapparatus of claim 1 further comprising the optical sensor disposedwithin the optical scanner body so as to capture, from the scanillumination reflected from the scanned object, an image of at least aportion of the scanned object.
 13. Apparatus for optical scanning, theapparatus comprising: an optical probe comprising an elongated cylinderof transparent material mounted upon an optical scanner body; at leastone source of scan illumination mounted on the probe proximally to thescanner body and disposed so as to project scan illumination distallythrough the probe away from the scanner body; a radially-reflectingoptical element mounted in the probe distally from the scanner body, theradially-reflecting optical element comprising a conical mirror on asurface of the radially-reflecting optical element proximal to thescanner body, the mirror oriented so as to project scan illuminationradially away from a longitudinal axis of the probe with at least someof the scan illumination projected onto a scanned object; a lens mountedin the probe between the radially-reflecting optical element and thescanner body and disposed so as to conduct to an optical sensor scanillumination reflected from the scanned object; and the optical sensormounted in the scanner body and disposed with respect to the lens so asto receive through the lens the scan illumination reflected from thescanned object.
 14. The apparatus of claim 13 further comprising opticalmasking material disposed on the exterior of the probe so as to maskscan illumination noise.
 15. The apparatus of claim 13 wherein: thesource of scan illumination is mounted on the exterior of the probe anddisposed so as to project scan illumination at an angle with respect toa longitudinal axis of the probe; and the conical mirror of theradially-reflecting optical element is an asymmetric conical mirror. 16.The apparatus of claim 13 further comprising the optical sensor disposedwithin the optical scanner body so as to capture, from the scanillumination reflected from the scanned object, an image of at least aportion of the scanned object.
 17. The apparatus of claim 13 furthercomprising a controller operatively coupled to the optical sensor, thecontroller configured to determine, from the scan illumination reflectedfrom the scanned object, measurements of the scanned object.
 18. Theapparatus of claim 13 further comprising: the source of scanillumination mounted in the probe proximally to the scanner body anddistally with respect to the lens and disposed so as to project scanillumination distally with respect to the lens and transversely throughthe probe to a mirror; and the mirror disposed with respect to thesource of scan illumination so as to reflect the scan illuminationlongitudinally through the probe away from the lens, away from thescanner body, and toward the radially-reflecting optical element. 19.The apparatus of claim 13 further comprising: the source of scanillumination mounted in the probe proximally to the scanner body withrespect to the lens and disposed so as to project scan illumination pastthe lens through an optical conductor; a first mirror disposed withrespect to the optical conductor so as to reflect the scan illuminationdistally with respect to the lens and transversely through the probe toa second mirror; and the second mirror disposed with respect to thefirst mirror so as to reflect the scan illumination longitudinallythrough the probe away from the lens, away from the scanner body, andtoward the radially-reflecting optical element.
 20. The apparatus ofclaim 13 further comprising the optical scanner body configured formounting upon an end effector of a robotic transport so that the probeis capable of movement by the robotic transport for optical scanningwith respect to the scanned object, including both movement within thescanned object and movement with respect to the exterior of the scannedobject.
 21. The apparatus of claim 13 further comprising the opticalscanner body configured to be hand held so that the probe is capable ofmovement by hand for optical scanning with respect to the scannedobject, including both movement within the scanned object and movementwith respect to the exterior of the scanned object.